Use Microsoft Exchange Server 2003 Load Simulator (LoadSim) as a benchmarking tool to simulate the performance load of MAPI clients. LoadSim allows you to test how a server running Exchange 2003 responds to e-mail loads. To simulate the delivery of these messaging requests, you run LoadSim tests on client computers. These tests send multiple messaging requests to the Exchange server, thereby causing a mail load. LoadSim is a useful tool for administrators who are sizing servers and validating a deployment plan. Specifically, LoadSim helps you determine if each of your servers can handle the load to which they are intended to carry. Another use for LoadSim is to help validate the overall solution.

Use Jetstress to verify the performance and stability of a disk subsystem prior to putting an Exchange server into production. Jetstress helps verify disk performance by simulating Exchange disk Input/Output (I/O) load. Specifically, Jetstress simulates the Exchange database and log file loads produced by a specific number of users. You use Performance Monitor, Event Viewer, and ESEUTIL in conjunction with Jetstress to verify that your disk subsystem meets or exceeds the performance criteria you establish. After a successful completion of the Jetstress Disk Performance and Stress Tests in a non-production environment, you will have ensured that your Exchange disk subsystem is adequately sized (in terms of performance criteria you establish) for the user count and user profiles you have established. It is highly recommended that the Jetstress user read through the tool documentation before using the tool.